title: Impact of male obesity on infertility: a critical review of the current literature.
abstract: OBJECTIVE
  To evaluate the current understanding of the effects and potential mechanisms of obesity on male fertility.
  
  
  METHODS
  Literature review of articles pertaining to obesity and male infertility.
  
  
  RESULTS
  Recent population-based studies suggest an elevated risk for subfertility among couples in which the male partner is obese and an increased likelihood of abnormal semen parameters among heavier men. Male factor infertility is associated with a higher incidence of obesity in the male partner. Obese men exhibit reduced androgen and SHBG levels accompanied by elevated estrogen levels. Reduced inhibin B levels correlate with degree of obesity and are not accompanied by compensatory increases in FSH. This complexly altered reproductive hormonal profile suggests that endocrine dysregulation in obese men may explain the increased risk of altered semen parameters and infertility. Additional features of male obesity that may contribute to an increased risk for infertility are altered retention and metabolism of environmental toxins, altered lifestyle factors, and increased risks for sexual dysfunction. Neither reversibility of obesity-associated male infertility with weight loss nor effective therapeutic interventions have been studied yet.
  
  
  CONCLUSIONS
  The increasing prevalence of obesity calls for greater clinician awareness of its effects on fertility, better understanding of underlying mechanisms, and eventually avenues for mitigation or treatment.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.
authors.forename: Ahmad O
authors.initials: AO
authors.lastname: Hammoud
authors.forename: Mark
authors.initials: M
authors.lastname: Gibson
authors.forename: C Matthew
authors.initials: CM
authors.lastname: Peterson
authors.forename: A Wayne
authors.initials: AW
authors.lastname: Meikle
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Carrell
mesh_terms: D015897:Comorbidity; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D015994:Incidence; D007248:Infertility, Male / Q000453:epidemiology* / Q000503:physiopathology*; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000503:physiopathology*; D018570:Risk Assessment; D012307:Risk Factors; D013076:Sperm Count; D013081:Sperm Motility
chemical_list: D012739:Gonadal Steroid Hormones